A general kinematic framework for mobile-linkage robotic systems (MLRS)

Conventional mechanisms (linkages) are typically characterized by the presence of a frame that remains fixed with respect to an inertial reference system. In contrast, mobile robotic systems, including articulated robots, consist of assemblies of rigid bodies that are free to undergo planar motion. The integration of these two paradigms leads to a class of mechanical systems in which a linkage structure is itself capable of moving on the plane. Such systems are hereafter referred to as Mobile-Linkage Robotic Systems (MLRSs). In an MLRS, the wheels not only provide locomotion but also actively participate in altering the kinematic configuration of the mechanism, resulting in a coupling between mobility and reconfiguration. This paper provides a theoretical framework of general validity, applicable to a broad class of MLRSs, independently of their specific mechanical realization. In particular, both direct and inverse kinematic formulations are provided.